On December 8th, 1981, troops of the Infantry Batalion Atlacatl, BIRI, (rapid reaction unit) arrived in Perquín. The commander in charge of the Battalion was Lieutenant Coronel Domingo Monterrosa Barrios, now deceased. The officer in charge of the operation was Major Natividad de Jesús Cáceres Cabrera. The contingent arrived with about six hundred troops.